Behind the chipped facades and rusted iron filigree of many of Havana's humblest-looking homes lie stashes of fabulous electronics equipment: cellphones, new computers, CD players, a VCR or two, perhaps even a DVD player.

This hidden infrastructure supports a thriving black market of information and entertainment. These days, the illicit traffic of carpets, chairs and computer parts that has long swirled through Havana's crumbling streets also contains the latest movies, music and art.

It is a dispersed, uncontrollable current in a nation that keeps a tight hand on the means of mass communication. At 8 o'clock each night, Cuba's four state-run television channels all show the same news program. The government controls the radio and the Communist Party daily, Granma, and it decides what films to produce, what CD's to put out and what movies to distribute.

But in the Playa section of Havana, a man rents pirated videos from his house. Up a rickety staircase in the Santo Suarez section is the hip-hop producer Pablo Herrera's home-recording studio. An artist who calls himself Zeus keeps a hard drive at home with the ''Godfather'' trilogy and ''The Lord of the Rings.'' The CD's in his sizeable collection all have the same blank silver faces. ''I did not buy one of them,'' he said.

While most of the goods that flow through this grassroots distribution network are benign, from the point of view of the Cuban government, some are not. Last year, for example, Ian Padron, a young Cuban filmmaker, made a documentary about baseball, ''Fuera de Liga'' (''Out of This League''), which included controversial material about defectors and difficult living conditions in Cuba. The Cuban government's film institute produced the documentary but declined to distribute it. Still, it seems as if everyone in Havana has seen it.

''I have a copy of that film,'' said a retired diplomat who spoke on condition of anonymity. ''Everybody has a copy of that film.''

The government's official position is that censorship does not exist in Cuba, and it is impossible to prove why Mr. Padron's film never hit the big screens of government-run movie theaters. Mr. Padron and several officials from the Ministry of Culture declined to comment.

It is true that despite the crackdown last year on political dissidents, when 75 people were sentenced to prison terms of up to 28 years (14 of them have been released, seven in the last few weeks), the Cuban government remains surprisingly tolerant of artistic expression. Last year, Fernando Perez's film, ''Suite Habana,'' which took an unflinching look at the hardships of daily life in Cuba, played to packed audiences at official theaters in Havana, and musicians recently tackled issues like racism and prostitution with bold irreverence at a government-supported hip-hop festival.

That does not mean there isn't censorship. But for now, while artists who step into forbidden territory may not make it onto state-run television or radio, they can use a vast, unsupervised grassroots distribution network to get their work out.

''Fuera de Liga'' was not the only film spirited through the nation's underground video stores. Pirated copies of ''Before Night Falls,'' the 2000 film about the persecuted Cuban poet Reinaldo Arenas, and ''Comandante,'' Oliver Stone's 2003 documentary about Fidel Castro, also made their way quietly around the island. The hip-hop group Clan 537's ''Quien Tiro la Tiza?'' (''Who Threw the Chalk?'') was never released domestically, but it still became a hit with young Cubans. ''You can ask any young Cuban if they know that disc,'' said Darsi Fernandez Maceira, the representative in Cuba of the Sociedad General de Autores y Editores, a management group that defends the intellectual property of its 66,000 member artists worldwide. ''They do. The demo went through the whole country.''

Pedro Luis Ferrer, a musician who advocated a multiparty system in one of his songs and paused for a moment of silence at a concert to honor Ronald Reagan, has not had a disc produced by a Cuban label since the late 1980's, and, he says, he hasn't been on Cuban television since the early 1990's. Some but not all of his songs are played on the radio.

''Some songs I sing at my concerts, hundreds of people sing them, but they've never been broadcast by TV or radio,'' he said. ''This means society, when it comes to spreading the word, is not passive. It's active.''

While effective, piracy is not especially lucrative for artists, and it is a mixed blessing for those whose work is given away. ''I don't feel like anyone is stealing from me,'' said Mr. Ferrer. ''It's true I'm not receiving money for it, but sometimes even recording labels don't pay you. At least I can feel freer.''

Luis Najmias, the editor of ''Fuera de Liga,'' had mixed feelings about the popularity of his unreleased film. ''It's good because people see the film,'' he said. ''It's bad because it's not the normal way of seeing the film, with good sound and picture.''

The development of these alternative distribution networks has been fueled, in part, by economic necessity. CD's in official stores are too expensive for most Cubans, and pirated copies are sold on the street for $3.

Underground video stores are cheaper, a boon to Cubans, whose monthly salaries typically amount to about $15. They have also grown out of the failure of government-run businesses to serve the Cuban market, especially when it comes to music. ''Almost all music distribution in Cuba is alternative,'' said Ms. Fernandez Maceira. ''Cuba has a great school of music and a great musical tradition, but within the country there are few possibilities for distribution.''

Why the government has such a high tolerance for artistic dissent is complex. The boundary between the permitted and the forbidden has shifted, and official sanction sometimes seems to be meted out idiosyncratically. Despite recent rumblings of a growing hard line within the world of culture, many Cuban artists today feel that the persecutions of the 1970's, dubbed the ''gray decade'' for the Soviet-influenced repression of the era, will not be repeated.

In August, the hip-hop collective El Cartel was able to perform only one of three songs, all of which were heavy with social critique, on state-run television.

''You could say there's censorship because two songs didn't make it on the air,'' said Mr. Herrera. ''But one song was played. Having that kind of art on TV makes a statement.''

Culture is, after all, one of the victories of the revolution. And even as the government has enacted regressive political and economic measures over the last year or so, including a moratorium on new licenses for many private businesses, Fidel Castro has embarked on an ambitious new plan to promote the arts.

Like data showing low infant mortality in Cuba, international success in the arts gives the state a measure of respectability, which, in turn, may buy artists some freedom.

''Carlos Varela sings the same things that Raul Rivero says,'' said the retired diplomat, comparing a popular Cuban musician with the poet and journalist who was sentenced to a 20-year jail term last year and is among the dissidents who have been released. ''Why Varela is allowed is very difficult to understand. And I don't see much difference between Varela and Ferrer.''

In his song, ''Vamos a Mejorar'' (''Let's Make It Better''), Mr. Ferrer baldly advocates a multiparty democracy: ''Who could imagine a perfect paradise with a single truth and a single thought?'' ''Let's improve our way of doing by making full democracy,'' the song continues.

Unlike most of the dissidents arrested last year, Mr. Ferrer, who has a CD coming out in the United States next month, can record tracks in his home recording studio, and his dissident message may even raise sales overseas.

''If I get into trouble,'' said Mr. Ferrer, ''it's because of my politics, not my art.''

In the meantime, his fans in Cuba can sing along. ''The artist is thunder,'' Mr. Ferrer said. ''And the people are wind.''

Erika Kinetz

I am the Shanghai correspondent for the Associated Press. I write mostly about transnational criminal networks thiving in the shadows of China's rise, with specific attention to the opioid trade, counterfeiting and money laundering.